In the era of the Internet, political communication becomes increasingly complex due to an abundance of available information. Moreover, many people evaluate politics as complex in a globalized world. The present study examined whether the perceived complexity of political issues would be related to individuals’ political Internet use and political knowledge. Further, we investigated the associations of three key psychological concepts with political Internet use and political knowledge acquisition in light of the potential perceived complexity of political issues: time affluence, informational self-efficacy, and need for cognition (NfC). Findings are based on a national online survey of 1082 German Internet users. The degree of perceived complexity was weakly associated with political knowledge but was not related to political Internet use. Political Internet use, time affluence, and NfC were positively related to political knowledge, and informational self-efficacy predicted political knowledge through an increase in political Internet use. The perceived complexity of politics did not moderate the relation between these psychological concepts and political Internet use. We discuss theoretical and practical implications and future research directions.